Terrorist actions often strike building and civil critical infrastructures of strategic interest, such as government buildings, airports, harbors, bridges, head offices of large corporations. The same buildings and critical infrastructure are often among the facilities damaged in a natural disaster. During such events the above facilities may exceed their functional or structural limits and this can be visible. On the other hand, they can also suffer enormous damage to their capacity without producing any apparent visible signs. Such damage, for instance, in the case of an earthquake, can render the facility incapable of surviving consecutive aftershocks. These aftershocks take place within few hours or days of the earthquake and can have an intensity of up to 90% of the earthquake intensity.

The post-crisis damage assessment process for constructed facilities is based mainly on on-site inspection by experienced engineers. When the visible signs of damage are not of the kind that points to a definitive damage or non damage state, further analysis is necessary. The problem is compounded by the shortage of experienced inspectors and the inevitable time delay caused by an in-depth structural analysis during which time a conservative position has to be taken and the facility stays closed. This is extremely painful in the case of critical facilities, such as, for instance, buildings necessary for the planning and management of early and full recovery (e.g., the Ministry of the Interior, or civil protection agencies), or hospitals, police and fire stations, bridges and tunnels essential for the passage of emergency vehicles.

RECONASS will provide a monitoring system for constructed facilities that will provide a near real time, reliable, and continuously updated assessment of the structural condition of the monitored facilities after a disaster, with enough detail to be useful for early and full recovery planning. The above assessment will be seamlessly integrated with automated, near real-time and continuously updated assessment of physical damage, loss of functionality, direct economic loss and needs of the monitored facilities and will provide the required input for the prioritization of their repair.

Advances in Information and Communication Technologies

In case of large scale events (e.g., an earthquake or regional conflict), recent advances in Information and Communication Technologies, including Earth Observation, can shorten the time for an initial inspection to identify damaged constructed facilities. For instance, following the 2010 Haiti earthquake, vertical aerial imagery of 0.15 m resolution allowed damage delineation that was an order of magnitude more accurate than that generated based on 0.5 m satellite imagery. Still, this is information that is based exclusively on what can be seen from outside the facility and can replace a first, rapid inspection, to quickly screen out the obviously safe and the obviously unsafe facilities, that usually takes some days. Following the Haiti earthquake also the utility of multi-view oblique aerial imagery from the Pictometry system to detect and quantify structural damage of buildings was assessed. This work has shown that physical damage to roofs and facades can be identified (visual signs of damage, as well as damage revealed by geometric deformation such as tilting). Systems such as Pictometry, but in principle any airborne imaging system that permits controlled oblique image acquisition, allow a building to be imaged from all four sides (barring occlusion by vegetation or closely-spaced buildings) and from above. While this potentially allows a comprehensive appraisal of the state of a buildings, it cannot replace the detailed inspection that follows to provide a more reliable estimate of the structural condition of the facility that takes some weeks.

In RECONASS the detailed assessment of damage in the monitored facilities will be used for the speedy local calibration of satellite and oblique aerial photography dramatically reducing the required time to inform the post disaster/crisis needs assessment process and provide base data for reconstruction efforts.

The above will be part of the RECONASS next generation post-crisis needs assessment tool in regards to construction damage and related needs. This tool will enable fusion of external information, allow for future expansion of the system, provide international interoperability between the involved units for reconstruction and recovery planning and support the collaborative work between these actors.

Objectives

To develop a monitoring system for constructed facilities that, along with the civil engineering software that will also be developed, will provide, automatically, a reliable, near real-time assessment of the structural condition and damage of both the structural componentsand the structural system of the monitored facility as a whole, after a disaster

To develop , based on the above estimates of the structural damage, a methodology and the corresponding software implementation for the automatic, near real-time estimation of the resulting non-structural damage,the functionality of the facility, the total volume of debrisfrom both structural and non-structural components in the monitored facilities, the cost and duration of structural and non-structural repairs and construction manpower and materials needs.

To continuously update the estimates of structural damage and needs for monitored facilities.

To provide seamless interoperability among heterogeneous networks to secure that the required information from the monitored facility can reach, in near real-time, the base-station (and more specifically, a module on Structural Assessment), even under difficult conditions, such as post-crisis situations (e.g., in a post-earthquake situation).

To use sensor-based damage assessment of the monitored facilities for the calibration and validation of remote sensing methods.

To develop a Post Crisis needs assessment tool in regards to Construction Damage and related Needs (PCCDN)that will collect information from all the monitored facilities in the affected region (e.g., the parliament, the Ministry of the Interior, hospitals, bridges) and process it in order to provide recovery stakeholders with near real-time, reliable, continuously updated information, in the form that each one of the stakeholders’ needs it, on structural and non-structural damage, shoring and demolition needs, loss of functionality, direct economic loss and the resulting needs in construction labor and materials for the monitored buildings. Moreover, damage information from the monitored buildings will be used to calibrate and validate spaceborne and airborne damage maps of the monitored buildings and the surrounding affected area in case of an extensive event, so that calibrated and validated such maps will be produced and offered by the PCCDN Tool in a much reduced time. Furthermore, this Tool will enable fusion and integration of relevant external data and information, allow for customization and future expansion of the system, provide international interoperability and allow for collaborative work between the civil agencies/authorities and the relief units

The technology in RECONASS, which will permit the near real-time, continuous and reliable assessment of the structural condition of monitored constructed facilities after a disaster, will be implemented in this work in the case of reinforced concrete buildings subjected to seismic, blast and impact loading and fire. However, after a successful conclusion of this project, this work will be extended to cover additional materials, e.g., steel, additional infrastructure, e.g., bridges or tunnels, and additional loadings, e.g., wind loads, tsunamis or land sliding.

Monitoring based on spatially discrete sensor nodes that measure continuously information on physical structural damage will eventually also allow other parameters to be added (e.g., chemical sensors) that, coupled with remote sensing, will allow an assessment of the entire area affected by a crisis situation based on low temporal resolution but synoptic image data, calibrated by high temporal resolution discrete sensor measurements. Specifically, the utility of the sensor networks will be further increased by using it as a backbone for another, distributed, sensor network.A single node in each of the sensor-monitored buildings (affixed on the outside of the building) equipped with a suitable sensor to detect dangerous chemical or biological traces de facto creates a new sensor network that spans all monitored buildings, and will give an overview of the distribution of the hazardous agent. Satellite imagery or existing cadastre information can then be used to assess the number of buildings (or people, if detailed registration data exist) exposed to the threat, and be further coupled with current weather data to predict further development of the hazardous agent, or assess the threat in areas not covered by sensors.

Expected results and impacts

RECONASS will improve reconstruction and recovery planning capabilities by providing a tool (PCCDN) that is faster and technologically improved as available today. More specifically:

It will provide a near real time structural assessment of the monitored building that will be detailed enough to replace both the initial and in-depth on-site structural assessment, that will be continuously updated to account, e.g., in the case of an earthquake, for foreshocks, main shocks and subsequent aftershock sequences and that will be credible so that authorities can start acting on it.

It will provide in 7 days (depending on satellite availability and UAV deployment time), as opposed to several months now, calibrated damage maps for the first draft of a complete post-crisis needs assessment.

It will offer the ability to monitor facilities with high value as terrorist attacks in a way that can provide in near real time after the attack an in-depth assessment of their structural condition. This will be based on local positioning tags on the structural members whose position before and after the attack will reveal the structural system that has emerged from the attack.

It will provide software component interoperability so that managers from various organizations can use the PCCND Tool.

It will be seamlessly integrated to existing national monitoring systems.

It will contain a plug and play sensor abstraction layer that will incorporate any kind of sensors independently of the used technology.

The above will have significant social and economic consequences that include:

Relief organizations, insurers and banks can begin funding restoration efforts at a much earlier date.

Reconstruction activities will start earlier.

It will be easier to obtain international financing soon after the disaster when the disaster is still in the news.

Emergency response crews will be provided with critical and timely information on damage in monitored facilities so that danger can be pinpointed and emergency response directed with precision.

Disaster cost will be reduced by preventing monitored structures from collapsing to limit damage to adjacent structures and additional loss of life when explosive devices impact highly populated urban centers.

Disaster costs will also be reduced when providing shoring to weakened monitored buildings to protect them from the aftershock sequence.

Safety will be promoted when dangerous monitored buildings or portions thereof will be demolished.

Knowledge of the structural condition of monitored buildings will reduce likely building-closure durations and consequently business interruption costs.

Identification of the safe monitored buildings for immediate use will help the government find the physical infrastructure needed to provide essential services.